We propose to conduct a prospective cohort study to investigate the association between widow inheritance and HIV infection among the Luo ethnic community in Kenya--the community with the highest HIV prevalence in the country. The specific aims of the study are to: 1) assess the association between widow inheritance and acquisition of HIV; 2) examine the relationship between HIV infection and being inherited by a brother-in-law versus by a 'professional' inheritor; 3) evaluate the difference in HIV risk associated with being inherited for companionship and support versus for sexual cleansing; and 4) identify correlates of inheritance overall, as well as of the different types of the practice. To achieve these aims, we will recruit 992 widows through radio announcements; women's, widow's and church groups; fliers, posters and brochures; health talks in clinics; chiefs' community meetings; and Focus Group Discussions with widows. At visit 1, those who consent will be counseled and tested for HIV. Those seronegative and are willing to join the study will come for visit 2 when they will be interviewed on their sociodemographic characteristics, sexual behavior, and medical history. They will also provide blood specimens for gonorrhoea, HSV-2, syphilis, and trichomonas virginals tests. Swabs will be taken from those with genital ulcers to test for haemophillus ducreyi. They will then be followed up quarterly for 24 months, during which time the activities performed at enrolment will be repeated. Exposure will be inheritance, including the different types of the practice, while the main outcome will be HIV seroconversion rate and the secondary outcomes will be the incidence of the various types of STIs. We shall use Epi-lnfo software to enter data and to perform crude and adjusted ManteI-Haenszel tests to obtain the relative risk of acquiring HIV and STI given that a widow is inherited relative to those not inherited. Logistic regression analysis will be used to identify which characteristics are independently related to inheritance. The findings will be the first scientific study of this association and will help in designing HIV intervention programs that are informed by research.